Fiber optic connector assembly

ABSTRACT

A fiber optic connector assembly is adapted for terminating at least one optical fiber of a fiber optic cable. The assembly includes a two-part elongated housing for receiving the fiber optic cable and defining a forward mating end and a rear end. The two parts of the housing extend along a substantial length of the housing through the rear end thereof. A ferrule is disposed within the forward end of the two-part housing for terminating the optical fiber. The two parts of the housing are juxtaposed and are adapted for receiving a crimp ring thereabout at the rear end of the housing. A pair of transversely spaced, complementarily engageable latches are operatively associated between the two housing parts. The pair of latches are disposed inside the outer profile of the housing and straddling opposite sides of the cable.

FIELD OF THE INVENTION

This invention generally relates to the art of fiber optic transmissionand, particularly, to a fiber optic connector assembly.

BACKGROUND OF THE INVENTION

Fiber optic connectors of a wide variety of designs have been employedto terminate optical fiber cables and to facilitate connection of thecables to other cables or other optical fiber transmission devices. Atypical fiber optic connector includes a ferrule which mounts andcenters an optical fiber or fibers within the connector. The ferrule maybe fabricated of such material as ceramic. A ferrule holder or otherhousing component of the connector embraces the ferrule and may befabricated of such material as molded plastic. A spring may be disposedwithin the housing or ferrule holder such that the ferrule is yieldablybiased forwardly for engaging another fiber-mounting ferrule of a matingconnecting device.

A pair of fiber optic connectors or a connector and another opticalfiber transmission device often are mated in an adapter which centersthe fibers to provide low insertion losses. The adapter couples theconnectors together so that their encapsulated fibers connectend-to-end. The adapter may be an in-line component, or the adapter canbe designed for mounting in an opening in a panel, backplane, circuitboard or the like.

The present invention is directed to various improvements in suchoptical fiber apparatus.

SUMMARY OF THE INVENTION

An object, therefore, of the invention is to provide a new and improvedfiber optic connector assembly for terminating at least one opticalfiber of a fiber optic cable.

In the exemplary embodiment of the invention, the connector assemblyincludes a two-part elongated housing for receiving the fiber opticcable. The elongated housing defines a forward mating end and a rearend. The two parts of the housing extend along a substantial length ofthe housing through the rear end thereof. A ferrule is positioned withinthe forward end of the two-part housing for terminating the opticalfiber. The two parts of the housing are juxtaposed and are adapted forreceiving a crimp ring thereabout at the rear end of the housing. A pairof transversely spaced, complementarily engageable latch means areoperatively associated between the two housing parts. The pair of latchmeans are disposed inside the outer profile of the housing and straddleopposite sides of the cable therewithin.

As disclosed herein, the latch means comprise a pair of latch armsdisposed immediately on opposite sides of the cable when the cable isassembled in the housing. The latch arms project from one housing partand include latch hooks for snap-latch engagement with latch bosses onthe other housing part. At least one of the housing parts includes atleast one alignment post for insertion into an alignment hole in theother housing part in a direction generally transversely of the cable.

Other objects, features and advantages of the invention will be apparentfrom the following detailed description taken in connection with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of this invention which are believed to be novel are setforth with particularity in the appended claims. The invention, togetherwith its objects and the advantages thereof, may be best understood byreference to the following description taken in conjunction with theaccompanying drawings, in which like reference numerals identify likeelements in the figures and in which:

FIG. 1 is a perspective view of the adapter assembly;

FIG. 2 is an exploded perspective view of the adapter assembly;

FIG. 3 is a vertical section taken generally along line 3--3 of FIG. 1;

FIG. 4 is a horizontal section taken generally along line 4--4 of FIG.1;

FIG. 5 is a top plan view of the adapter assembly;

FIG. 6 is a side elevational view of the adapter assembly;

FIG. 7 is a perspective view of the board connector insertable into oneend of the adapter assembly;

FIG. 8 is an exploded perspective view of the board connector;

FIG. 9 is a vertical section taken generally along line 9--9 of FIG. 7;

FIG. 10 is a vertical section taken generally along line 10--10 of FIG.7;

FIG. 11 is a top plan view of the cable connector;

FIG. 12 is a side elevational view of the cable connector;

FIG. 13 is a vertical section taken generally along line 13--13 of FIG.11;

FIG. 14 is a horizontal section taken generally along line 14--14 ofFIG. 12;

FIG. 15 is a top plan view of the bottom housing part of the cableconnector;

FIG. 16 is a vertical section taken generally along line 16--16 of FIG.15;

FIG. 17 is a bottom plan view of the upper housing part of the cableconnector;

FIG. 18 is a section taken generally along line 18--18 of FIG. 17;

FIG. 19 is a vertical section taken generally along line 19--19 of FIG.13; and

FIG. 20 is a vertical section taken generally along line 20--20 of FIG.14.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the drawings in greater detail, the invention is embodiedin a fiber optic connector/adapter assembly which includes three maincomponents, namely: an adapter assembly, generally designated 10 andshown in FIGS. 1-6; a board connector, generally designated 12 and shownin FIGS. 7-10; and a cable connector, generally designated 14 and shownin FIGS. 11-20. Adapter assembly 10 is designed for mounting in anopening 16 in a panel, backplane or circuit board 18 as seen in FIG. 3.Cable connector 14 is adapted for terminating a fiber optic cable 20.While board connector 12 is mounted on a circuit board 22 (FIG. 9), theboard connector also could be provided for terminating a fiber opticcable. However, for clarity purposes herein, connector 12 will bereferred to as the "board" connector and connector 14 will be referredto as the "cable" connector.

Referring first to FIGS. 1-6, adapter assembly 10 includes a housingfabricated of three components as best seen in FIG. 2, namely: a centeror main body, generally designated 24; a rear end receptacle body,generally designated 26; and a front end receptacle body, generallydesignated 28. Rear receptacle body 26 defines a first receptacle end 30(FIG. 3) for receiving board connector 12. Front receptacle body 28defines a second receptacle end 32 (FIG. 4) for receiving cableconnector 14. A pair of generally planar, rectangular shutter doors 34close and open first receptacle end 30 and a single generally planarrectangular shutter door 36 closes and opens second receptacle end 32.

Rear end receptacle body 26 of adapter assembly 10 is generallybox-shaped as seen in FIG. 2 and forms sort of an end cap fortelescoping over the rear end of main body 24 as seen best in FIG. 3. Apair of ramped latch bosses 38 on both the top and bottom of main body24 snap into pairs of latch apertures 40 at the top and bottom of rearreceptacle body 26. A pair of outwardly flared guide arms 42 projectrearwardly of rear receptacle body 26 for guiding board connector 12into first receptacle end 30 of the adapter assembly. As seen best inFIG. 2, a guide groove 44 is formed on the inside of rear receptaclebody 26 near each corner thereof, with the groove leading to a hole 44ain the respective side wall of the rear receptacle body.

Front end receptacle body 28 of adapter assembly 10 is formed as agenerally rectangular sleeve which slides over a generally rectangularprojecting portion 46 of main body 24 and sandwiches panel 18 betweenthe main body and the front end receptacle body as seen in FIGS. 3 and4. A ramp latch boss 48 on the top and bottom of projection 46 snapbehind ledges 50 at the front end of front receptacle body 28 to holdthe receptacle body onto the main body as seen best in FIG. 3. Singleshutter door 36 is pivotally mounted to front end receptacle body 28 bymeans of a pair of pivot trunions 52 (FIG. 2) which snap into holes 54in the receptacle body. A torsion spring 56 (FIG. 5) has opposite ends56a and 56b anchored to the shutter door and the receptacle body,respectively, for biasing the shutter door to its closed position shownin full lines in FIGS. 3 and 4. The shutter door can be manually openedas shown in phantom in FIG. 3 against the biasing of torsion spring 56.

Main body 24 of adapter assembly 10 includes a plurality of mountingposts 58 projecting forwardly of a flange 60 outside projecting portion46, for insertion into appropriate mounting holes (not shown) in panel18 (FIG. 3) to mount the main body within opening 16 in the panel. Apair of cantilevered latch arms 62 are provided for latchingly engagingcable connector 14.

Each of the pair of shutter doors 34 which close and open rearreceptacle end 30 of the adapter assembly include a pair of pivottrunions 64 projecting outwardly from opposite sides thereof as bestseen in FIG. 2. In assembly, the pair of shutter doors are mountedwithin rear receptacle body 26 by sliding pivot trunions 64 into guidegrooves 44 until the pivot trunions snap into holes 44a in the sidewalls of the rear receptacle body. This allows for very easy assembly ofthe shutter doors within the adapter assembly. In other words, rearreceptacle body holds the shutter doors as a subassembly which can beassembled as a unit to main body 24. A U-shaped torsion spring 66 spansthe back side of each shutter door 34, with ends of the torsion springanchored to rear receptacle body 26 to bias the shutter doors to theirclosed positions as shown in FIG. 3. The shutter doors pivot about pivottrunions 64 to open positions as shown in FIG. 3, in response toinsertion of board connector 12 into rear receptacle end 30 of theadapter assembly.

The invention contemplates that shutter doors 34 overlap each otheralong their inner edges, as at 68 in FIG. 3, when the shutter doors arein their closed position. This positively ensures against light leakagealong an optic axis 69 extending centrally through the adapter assembly.Dust also does not migrate to the interior of the adapter assembly. FIG.3 shows the top shutter door overlapping the outside of the bottomshutter door. However, depending upon the sequence of closure, thebottom shutter door just as well could overlap the outside of the uppershutter door. Finally, the shutter doors are relieved, as at 70, alongtheir inner edges for purposes described hereinafter.

The use of a pair of opposing shutter doors 34, versus a single door,has a number of advantages. First, the two doors save considerable axialspace which otherwise would be required to accommodate the full pivotingaction of a single door which would be twice as big as each of the pairof doors. Second, it is easier to open the two smaller doors becausesmaller springs can be provided. The connector is biased by the doors tothe center and, thereby, most forces are applied near the edges of thedoors, whereas with a single door a large force is required on one sideof the centerline than the other side. Third, the wiping surface ofeither of the pair of doors 34 is one-half the wiping surface of asingle door. With the single door, dust collected on the outside of thedoor is carried all the way toward the interface area between theconnectors. With the two doors, any dust which accumulates on the outersurfaces thereof will be deposited primarily on the sides of the boardconnector rather than being carried interiorly by the mating face of theboard connector.

Each of the main body 24, the rear end receptacle body 26, the front endreceptacle body 28, each of the shutter doors 34 and the single shutterdoor 36 is a one-piece structure unitarily molded of dielectric materialsuch as plastic or the like.

FIGS. 7, 9 and 10 show board connector 12 in assembled condition, andFIG. 8 shows various components of the board connector. Moreparticularly, FIG. 8 shows the board connector to include an inner,two-part housing, generally designated 72, which includes a base housingpart 74 and a cover housing part 76; an outer board frame, generallydesignated 78; as well as a front shroud 80, a ferrule 82, a pin holder84 and a pair of alignment pins 86. In assembly, a multi-fiber opticcable 87 (FIGS. 9 and 10) is terminated in ferrule 82; alignment pins 86are anchored in pin holder 84, with the alignment pins projectingthrough the ferrule as seen best in FIG. 10, and this subassembly of thecable, ferrule, pins and pin holder are mounted within housing base 74in the position shown in FIG. 10. Head portions 86a of the pins areanchored within passages 84a of pin holder 84. A pair of coil springs 88surround posts 84b of pin holder 84 and abut against interior walls 74aof housing base 74 to bias the pin holder, ferrule and cable forwardlywithin the board connector. Abutment shoulders are provided, as at 90 inFIG. 10, between ferrule 82 and housing base 74 to define the forwardlimit position of this subassembly. A front lip 76a of housing cover 76is positioned beneath a ledge 74b of housing base 74 as best seen inFIG. 9, to provide a fulcrum for pivoting the housing cover down ontothe housing base. A crimp ring 92, such as of metal material, then iscrimped onto the rear ends of the housing parts to hold the housingparts, ferrule, pin holder, alignment pins and fiber optic cable inassembled condition.

Outer board frame 78 of board connector 12 is assembled about innerhousing 72 in the direction of arrow "A" (FIG. 8). In assembly, theouter frame will abut the inner housing, as at 94 in FIG. 10, and a pairof latch arms 96 are cantilevered outwardly of housing base 74 forholding the outer board frame to the inner housing as seen in FIG. 10.Outer board frame 78 includes a plurality of depending board-mountingposts 78a as seen in FIG. 9, for insertion into mounting holes 22a inboard 22 to mount the board connector to the board. The outer boardframe has a pair of side arms 97, and guide arms 42 of the rearreceptacle body 26 of adapter assembly 10 mate on the outside of arms 97and move into slots 78a on the sides of the outer board frame.

Front shroud 80 of board connector 12 is mounted onto the front end ofinner housing 72 by means of a latch boss 98 (FIG. 9) on the interior ofthe front shroud and an abutment shoulder 100 on the top of housingcover 76. A pair of coil springs are sandwiched between the housing baseand cover and the shroud to bias the shroud forwardly. The coil springsare located in slots in the housing base and the housing cover. One ofthe slots 101 is visible in housing cover 76 in FIG. 8. A similar slotis in the housing base. The tops of the coil springs are visible in FIG.9, as at 103.

A novel feature of the invention is best shown in FIG. 9 wherein it canbe seen that the front end of shroud 80 is offset as indicated by arrows"B". In other words, a bottom edge 80a projects further outwardly than atop edge 80b of the shroud a distance indicated by arrows "B".Therefore, comparing FIG. 9 with FIG. 3, when board connector 12 isinserted into rear receptacle end 30 of adapter assembly 10 in thedirection of arrow "C" (FIG. 3), bottom edge 80a of shroud 80 willengage the bottom shutter door 34 before top edge 80b of the shroudengages the top shutter door. Similarly, when the board connector ispulled out of the adapter assembly, the top shutter door will pivot toits closed position prior to the pivoting action of the bottom shutterdoor, because of the offset front mating end of the board connector.Although sequential opening of the shutter doors is not all thatcritical, it is important that one of the shutter doors closes beforethe other shutter door, so that the edges of the shutter doors do notjam or abut and prevent complete closure. By offsetting the front edges80a and 80b of shroud 80, sequential closing of the doors is assured toensure that the doors overlap completely across optic axis 69.

When board connector 12 is inserted into rear receptacle end 30 ofadapter assembly 10, and shroud 80 engages shutter doors 34, provisionmust be made to prevent the tips of alignment pins 86 from engaging thedoors. As stated above, the inner edges of the doors are relieved at 70.This provides a recessed area into which the tips of the alignments pinproject without engaging the doors. The recessed area also protects thepolished ends of the fibers at the front face of ferrule 82.

Cable connector 14 is shown in FIGS. 11-20 and is constructed similar toboard connector 12, to the extent that cable connector 14 includes aninner two-part housing formed by a housing base 102 (FIGS. 15 and 16)and a housing cover 104 (FIGS. 17 and 18). Like the board connector, afront lip 104a of the cover is positioned beneath a ledge 102a of thebase as best seen in FIG. 13, to form a fulcrum about which the cover ispivotally mounted down onto the base. The two parts of the housingextend along a substantial length of the housing through a rear endthereof whereat a crimp ring 106, such as of metal material, can becrimped to hold the housing parts together. The crimp ring is showncrimped, as at 106a , in FIG. 19.

Again, like board connector 12, cable connector 14 includes a ferrule108 for terminating the fibers of a multi-fiber optic cable 110, a pinholder 112 anchoring the rear ends 114a of a pair of alignment pins 114which extend through the ferrule, and a pair of coil springs 116 forbiasing the pin holder, alignment pins, ferrule and cable forwardly ofthe assembled housing parts.

When assembling housing cover 102 to housing base 104 a plurality ofguide posts 102b (FIG. 15) are positioned within a plurality of guideholes 104b and guide recesses 104c (FIG. 17) in housing cover 104. FIG.20 shows guide posts 102b within guide holes 104b.

In order to secure housing base 102 and housing cover 104 in assembledcondition, the housing cover includes a pair of transversely spaced,hooked latch arms 110 which snap behind ledges 112 on housing base 102.This complementary interengaging latch means is shown best in FIG. 19.As seen in FIG. 14, when the housing base and cover are fully assembled,the latch arms will straddle opposite sides 113 of the fiber array 20aof cable 20. The latch arms, therefore, are disposed inside the outerprofile of the two-part housing so that the housing does not have to beenlarged to provide a latch means. Each of the two housing parts, namelyhousing base 102 and housing cover 104 is a one-piece structureunitarily molded of plastic material or the like.

A rear boot 114 of elastomeric material or the like is disposed aboutthe rear end of cable connector 14. The boot is a one-piece structurefabricated of somewhat flexible material to provide a strain reliefmeans at the rear of the connector and about cable 20. The rear of theboot includes finger-gripping exterior ribs 114a to facilitate grippingthe cable connector and inserting the connector into adapter assembly10. The boot is generally hollow and includes interior latches 114b(FIG. 14) for snapping behind latch flanges 116 of the two housingparts.

A pull latch 118 surrounds the inner two-part housing of cable connector14 for latching the cable connector to adapter assembly 10. A pair ofcoil springs 120 (FIG. 13) are captured in slots 121 (FIGS. 15 and 17)and bias the pull latch forwardly in the direction of arrows "D". Whenthe cable connector is inserted into the adapter assembly, the frontends of cantilevered latch arms 62 (FIG. 2) will engage the front ofpull latch 118 and bias the pull latch rearwardly against coil springs120 opposite the direction of arrows "D" until the cantilevered latcharms snap behind latch shoulders 122 (FIGS. 14 and 15) of housing body102. Latch arms 62 have inwardly offset latch hooks 62a (FIG. 2) whichsnap behind latch shoulders 122, whereupon pull latch 118 is biased backforwardly by coil springs 120. The front end of the pull latch will thenmove over the top of hooked ends 62a of the latch arms to prevent thelatch arms from moving out of their locked position behind shoulders122. When it is desired to disconnect cable connector 14 from adapterassembly 10, pull latch 118 is pulled rearwardly opposite the directionof arrows "D" whereupon latch arms 62 are free to move transverselyoutwardly away from latch shoulders 122 and allow the cable connector tobe pulled out of the adapter assembly.

It will be understood that the invention may be embodied in otherspecific forms without departing from the spirit or centralcharacteristics thereof. The present examples and embodiments,therefore, are to be considered in all respects as illustrative and notrestrictive, and the invention is not to be limited to the details givenherein.

We claim:
 1. A fiber optic connector assembly for terminating at leastone optical fiber of a fiber optic cable, comprising:a two-partelongated housing for receiving the fiber optic cable and defining aforward mating end and a rear end, the two parts of the housingextending along a substantial length of the housing through the rear endthereof; a ferrule within the forward end of the two-part housing forterminating the optical fiber; the two parts of the housing beingjuxtaposed and adapted for receiving a crimp ring thereabout at the rearend of the housing; and a pair of transversely spaced, complementarilyengageable latch means operatively associated between the two housingparts, the pair of latch means being disposed inside the outer profileof the housing and straddling opposite sides of the cable therewithin.2. The fiber optic connector assembly of claim 1 wherein said latchmeans comprise a pair of latch arms disposed immediately on oppositesides of the cable when the cable is assembled in the housing.
 3. Thefiber optic connector assembly of claim 2 wherein said latch armsproject from one housing part and include latch hooks for snap-latchengagement with latch bosses on the other housing part.
 4. The fiberoptic connector assembly of claim 1 wherein at least one of the housingparts includes at least one alignment post for insertion into analignment hole in the other housing part in a direction generallytransversely of the cable.
 5. A fiber optic connector assembly forterminating at least one optical fiber of a fiber optic cable,comprising:a two-part elongated housing for receiving the fiber opticcable and defining a forward mating end and a rear end, the two parts ofthe housing extending along a substantial length of the housing throughthe rear end thereof, and the two parts of the housing each being aone-piece structure unitarily molded of dielectric material; a ferrulewithin the forward end of the two-part housing for terminating theoptical fiber; a pair of transversely spaced, complementarily engageablelatch means operatively associated between the two housing parts, thepair of latch means being disposed inside the outer profile of thehousing and straddling opposite sides of the cable therewithin; and ametal crimp ring clamped about juxtaposed rear ends of the two housingparts.
 6. The fiber optic connector assembly of claim 5 wherein saidlatch means comprise a pair of latch arms disposed immediately onopposite sides of the cable when the cable is assembled in the housing.7. The fiber optic connector assembly of claim 6 wherein said latch armsproject from one housing part and include latch hooks for snap-latchengagement with latch bosses on the other housing part.
 8. The fiberoptic connector assembly of claim 5 wherein at least one of the housingparts includes at least one alignment post for insertion into analignment hole in the other housing part in a direction generallytransversely of the cable.
 9. A fiber optic connector assembly forterminating at least one optical fiber of a fiber optic cable,comprising:a housing for receiving the fiber optic cable and defining aforward mating end for mating with a complementary connecting device; aferrule within the forward end of the housing for terminating theoptical fiber; a pin holder within the housing behind the ferrule; apair of alignment pins held by the pin holder on opposite sides of thecable and extending through the ferrule for aligning the connector withthe complementary connecting device; and a pair of springs on oppositesides of the cable and sandwiched between the housing and the pin holderfor biasing the pin holder and, thereby, the ferrule forwardly relativeto the housing.